1. Field of Invention
This invention relates to wall and partition construction with either load bearing or non-load bearing wall design criteria in single or multi-story buildings where there is a need to confine a fire and prevent its spreading.
2. Description of the Prior Art
In normal building construction, particularly of the multi-story type, and more particularly in such construction where corrugated metal with or without concrete are formed into slabs and decks to form successive floors and/or roof assemblies. There is a physical condition and design criteria that floor slabs and/or roof decks must follow which allows for deflection or "sag", due to the passage of time or as a reaction to specific live loads, dead loads, or some other catastrophic building movement i.e. earthquakes, wind, fire, etc. In the construction of such buildings, partitions are designed and installed, in general practice, to either withstand these forces or to accommodate the anticipated movement. These partitions may be comprised of gypsum lath and plaster, wallboard with metal or wood framing, masonry units of various sizes, concrete, and a host of other material including but not limited to cement boards, fiber boards, and other well-known materials. Variability in the deflection or "sag" of the concrete ceiling or floor construction creates unique problems in the installation of partitions. Problems relating specifically to the vertical movement of the slab deflection and specifically to the partition construction have been addressed in prior art. However, there is a problem which remains with these walls or partitions as to their ability to insure the integrity of their specified fire rating or fire resistancy in accordance with national and local fire codes.
In the construction industry this is a particularly difficult and time consuming detail in the construction of the fire rated partitions or walls required by code. Specifically wherein the underside of the ceiling or floor are usually comprised of a corrugated or preformed metal substrate over which the concrete is poured in a manner to form the successive floors and/or concomitant ceilings of a one story or multi-story building, or wherein the underside of the ceiling or roof comprises a corrugated or preformed metal substrate over which insulation and roofing materials are placed in such a manner to form a roof assembly. The non-load bearing interior walls are oftentimes running perpendicular to the corrugations and/or fluted substrate which forms the ceiling and thus presents a wall/ceiling joint having a plurality of apertures therethrough at the intersecting line. In other situations the non-load bearing interior wall may find itself running directly parallel or partially offset of parallel to the corrugated substrate such that there may in fact be a longitudinal gap between the top of the non-load bearing wall and the undersurface of the ceiling. Thirdly, the partitions in some instances may run oblique to the direction of the corrugations and/or flutes creating a plurality of apertures therethrough at the intersecting line each having its own unique size, shape, and depth.
Fire rated walls, by code and definition, are required to maintain their specified rating from the base of the floor to the underside of the deck or ceiling above. The deck as stated, comes in various sizes and oftentimes irregular shapes. The current performance criteria for a fire rated wall is found in UL Test Procedure 2079 which establishes minimal performance requirements for this design condition. The test procedure is designed to provide evidence of minimal performance in the following areas.
The first test is commonly referred to as cycling. This test is designed to simulate the movement that a building experiences through settling, temperature expansion and contraction, normal occupancy vibrations and possibly vibration of a construction origin. Specifically it calls for a vertical cycling movement of one half inch at ten cycles per minute for fifty minutes.
The second minimal performance requirement is that of temperature. This test is designed to simulate the expected temperature potential of a fire condition. Specifically it calls for a hot side of approximately 1,850.degree. F. with a cool side maximum temperature increase of 250.degree. above ambient for a period of two hours.
The third test requirement is referred to as hose stream. This test is designed to give a measure of the toughness of the fire flashing by simulating the effects of a water bath somewhat akin to that of a fireman's hose stream. Specifically the test calls for a two inch stream of water at 125 pounds of pressure at 30 feet for a second and a half per square foot of sample. To meet this test, the assembly must pass all three requirements.
In the past, attempting to fireproof the intersection of a non-load bearing ceiling wall and the ceiling above it, which might be of irregular shape, required individuals to move along the wall ceiling intersection from point to point and hand fill any of the apertures or openings which might be present with a fiber packing of 4 to 8 pounds density and then cover each side of the packing with a special fire caulk. This was not only time consuming and costly, but also did not always result in a uniform fill which would meet the criteria of the aforementioned test.
Applicant has developed a structural member and assembly which meets the aforesaid test criteria, is easily installed and would significantly reduces labor and installation costs, and has built in quality control points.